Struct Cursor 

pub struct Cursor<'a> { /* private fields */ }

Stateful, zero-copy cursor over an immutable byte slice.

All methods advance the cursor in-place and return sub-slices that borrow from the original input — no allocation, no memcpy.

Implementations

impl<'a> Cursor<'a>

pub const fn new(data: &'a [u8]) -> Self

Create a new cursor starting at position 0.

pub const fn position(&self) -> usize

Current byte offset from the start.

pub const fn remaining(&self) -> usize

Number of bytes remaining in the buffer.

pub const fn is_empty(&self) -> bool

true if there are no more bytes to read.

pub fn as_slice(&self) -> &'a [u8]

Return the unread portion as a slice without advancing.

pub fn read_bytes(&mut self, n: usize) -> ParseResult<&'a [u8]>

Borrow exactly n bytes and advance the cursor.

This is the core primitive — O(1), zero-copy.

pub fn read_u8(&mut self) -> ParseResult<u8>

Read a single byte.

pub fn read_u16_le(&mut self) -> ParseResult<u16>

Read a little-endian u16.

pub fn read_u32_le(&mut self) -> ParseResult<u32>

Read a little-endian u32.

pub fn read_i32_le(&mut self) -> ParseResult<i32>

Read a little-endian i32.

pub fn read_u64_le(&mut self) -> ParseResult<u64>

Read a little-endian u64.

pub fn read_i64_le(&mut self) -> ParseResult<i64>

Read a little-endian i64.

pub fn read_varint(&mut self) -> ParseResult<u64>

Parse a Bitcoin-style variable-length integer (1, 3, 5, or 9 bytes).

Returns the decoded value as u64.

pub fn read_var_bytes(&mut self, max: usize) -> ParseResult<&'a [u8]>

Read a length-prefixed byte slice (varint + raw bytes).

Returns a zero-copy sub-slice of the original input.

pub fn read_array<const N: usize>(&mut self) -> ParseResult<&'a [u8; N]>

Borrow a fixed-size array from the current position.

Panics at compile-time if N == 0.

pub fn skip(&mut self, n: usize) -> ParseResult<()>

Skip n bytes without returning them.

pub fn split(&mut self, n: usize) -> ParseResult<Cursor<'a>>

Create a sub-cursor for exactly n bytes and advance the outer cursor.

Useful for reading a known-size payload and ensuring it is fully consumed.

Trait Implementations

impl<'a> Clone for Cursor<'a>

fn clone(&self) -> Cursor<'a>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Debug for Cursor<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.